The use of back-lighted panels for advertising purposes is generally well known and an accepted means for accentuating visual presentations in the promotion and sale of goods and/or services. That having been said, it is implicit in general commercial usage, that the illumination source will give off heat as an unavoidable byproduct. Heated filaments in incandescent lighting, as well as ballasts and bulbs in florescent lighting, all produce significant amounts of such heat. That heat, in most lighting applications, however, is not problematic, and can be dissipated to the ambient environment without significant penalty or any special design considerations. There are, however, applications where this axiom does not apply, and for which, as a consequence, the use of back-lighted illuminated signs are at the very least problematic, if not completely out of the question.
By way of example, coolers for storage of thermally sensitive materials are not readily adapted to be used in immediate conjunction with such signs, owing to thermal transfer from the heat-producing sign, to the cooler, and from there (barring any active intervention), to the thermally sensitive materials contained therein.
These problems are perhaps most acutely manifest in coolers, including such active appliances as refrigerators and especially freezers. Freezers are designed to accommodate a fairly narrow operating window of thermal loading. The proportionate amounts of evaporator and refrigerator coil radiating/absorbing surface areas and compressor capacity are specifically engineered systems for given a given freezer volume, insulation jacketing, and anticipated normal ambient temperature range loadings and usage frequency, in mind. Any operational departures from those design assumptions create manifest inefficiency in the freezers operation, leading at the very least to increased operating costs and early component failure, both of which are incompatible with modern concerns over environmental issues and inevitably also lead to increased capital expenses. Moreover, the cooling capacity of the device can be overloaded to the point where the quality of the contents stored in the freezer can be undesirably compromised. Where a stored product is damaged, any possible benefit that might have accrued through the illuminated advertising is likely to be offset or even undone, through loss of sales not only in the instance of the damaged product, but more importantly and in the longer term, through customer dissatisfaction.
Accordingly, there remains a need in the art for illuminated signs that can accommodate the thermodynamic problems of their association with a cooler. This is especially the case with inexpensive domestic type freezers which are particularly vulnerable, when employed in retail settings, to being adversely compromised by the heat given off by any such associated sign. This sensitivity arises from the fact that the inexpensive domestic freezers (characterized by having the heat radiating cools endbedded within the freezer walls and being therefore dependent on the cabinet surface area for heat exchange), are by virtue of their cost, attractive to persons wishing to employ them in retail settings. The frequency of use in the retail setting greatly exceeds the design assumption implicit in the design of a domestic freezer, and therefore represents an extreme taxation on the freezer's operating limits. The addition of an illuminated sign in association with the domestic freezer goes even beyond that, and calls into question the economic merits of associating the domestic freezer with a sign, in retail settings. Features and attendant advantages of the present invention will become apparent to those of ordinary skill in the art as the description thereof proceeds.